(1) Field of the Invention
The present invention relates to a retention and release mechanism providing a safety feature in ski boots. More specifically, the present invention relates to the prevention and mitigation of the severity of injuries to the anterior cruciate knee ligament. This invention also relates to a construction of the ski boot upper to provide a safe biomechanically natural rearward articulation.
(2) Description of the Prior Art
Various prior art devices have been described relating to improving against injury in the sport of downhill skiing. The vast majority of these disclosures relate to improvements in the ski binding; i.e. that mechanism which is affixed directly to the ski. In addition, there have been some disclosures regarding modification to the ski boot itself but more so from the point of view of providing a mechanism for the wearer to more readily step into and out of the boot. For example, in U.S. Pat. No. 5,136,794 there is reported a ski boot consisting of a lower part and of a shaft, in the form of a collar, which is articulated on the lower part and provided with at least one closing buckle. The shaft comprises, at the rear, a rocker which interacts with a stop which is integral with the lower part in order to lock the shaft in a position inclined forwards. The rocker is held in inactive position upon opening of the uppermost buckle by means of a cable and a spring. Thus, the shaft does not come to be locked at the wrong moment during walking.
Attention is also directed to U.S. Pat. No. 5,127,171, and art cited therein, which discloses a ski boot with a shell comprising a shaft in two parts, the rear part of which is connected, on the one hand, to the shell and, on the other hand, to the front part of the shaft by two pair of links. The axis of the articulations on the rear part are situated, in the closed position of the boot, on one side and the other of the plane containing the axes of articulation on the shaft and the front part of the shaft. It is possible to open the shaft wide for putting the boot on, while having only a limited tilting backwards of the rear part. The upper connection can be associated with a closing lever.
In U.S. Pat. No. 5,107,608, there is disclosed a ski boot for lessening the incidence of knee injuries which the boot is said to exert a forward directional force on the skier's leg. A releasing means changes the rigid support position for the foot and the lower leg on application of a predetermined level of force by the boot on the wearer. The '608 disclosure goes on to report that rearward pressure of the person's lower leg against the rear leg element of the boot can be sensed by force sensors producing electrical outputs by the use of piezoelectric material. In addition, as illustrated in FIG. 7 therein., a mechanical latch assembly employing a tension spring 96 is disclosed, which is described as urging or maintaining the device in ski position, and when said tension is overcome, a release position is obtained as shown in FIG. 8.
U.S. Pat. No. 5.283,964 discloses a boot device for front-to-back immobilization of the upper, which acts on an oscillating level capable of being supported against a stop on the shell base. The device is constituted by a rectilinear-motion control mechanism incorporating an external control device of which an inner part actuates via a cam a sensing device associated with the oscillating lever so as to impart to the latter an angular rotating movement around its pin toward a locked or release position in relation to the stop formed on the shell base.
Attention is also directed to following foreign patent documents: WO 92/05718 and 0514762A2. More specifically, in WO 92/05718 there is disclosed a ski boot for enhancing the safety of skiing. Finally, reference is made to EP-375-604-A, which discloses a ski boot with stop holding the leg forward, and French Patent 2647-649-A which discloses a ski boot with an articulated leg locked in a forward position, which leg is articulated having a clip at the back which pivots around the horizontal axis.
All of the above, however, are distinct from the present invention, in that they collectively fail to provide, in the boot itself, a practical mechanism for mitigation of knee injuries while used in skiing. Accordingly, in the context of the present invention, there is herein provided in the boot a retention and release mechanism which specifically reduces potentially injurious forces to the anterior cruciate knee ligament (ACL). Stated another way, the present invention is designed to provide a ski boot that allows the potentially damaging posterior forces at the spoiler (or upper shaft) section of a ski boot to be absorbed or transduced.
Therefore, it is an object of the invention to provide a ski boot design which restricts the posterior movement of the upper shaft of a ski boot, by allowing posterior travel of the same after a selected level or threshold of force has been obtained.
In addition, the present invention also contains as its objective the development of a unique mechanism to affect cuff displacement and arrest when appropriate to create a more safe environment and enhanced safety to the user.
Moreover, the present invention has as its object the preparation of a retention and release mechanism providing a safety feature in a ski boot design.
Finally, it is a more specific object of the invention to provide a ski boot design which prevents or mitigates the severity of injuries to the anterior cruciate knee ligament, and to provide a more safe natural biomechanical rearward articulation, in the boot, for the user thereof.